The Cardinello gorge, whose name signifies ´pivot of the valley´ derives it from the nearby Mt Cardine. It´s accepted that the first attempts to carve a way through the gorge was in 1643. However the creation of a viable route was not completed until after 1709, with the construction of tunnels, railing, canopies and roofs as protection against avalanches.
The Cardinello had already claimed the lives of beasts of burden, soldiers and pilgrims and remained by far the most dangerous section of the Via Spluga. It provoked quite a considerable stir during the passage of the French army led by General McDonald in December 1800 when despite a relentless blizzard 15,000 men managed to reach Splügen. But the effort resulted in the loss of many soldiers, swept away by landslides or by falling into the abyss. Isola, along with the villages of Montespluga and Pianazzo make up the municipality of Madesimo, itself a popular ski resort.
